2003 Chevrolet Blazer Owner's Manual - Page 16

On two-door models with an inside mounted spare tire, the driver's side rear seat head restraint must be lifted and held upright as the seatback is raised. Otherwise, the head restraint will hit the spare tire and prevent the seatback from properly latching. Push and pull on the head restraints to check that they have locked in the upright position. If they haven't, see your dealer for service. A safety belt that is improperly routed, not properly attached, or twisted won't provide the protection needed in a crash. The person wearing the belt could be seriously injured. After raising the rear seatback, always check to be sure that the safety belts are properly routed and attached, and are not twisted. If the seatback isn't locked, it could move forward in a sudden stop or crash. That could cause injury to the person sitting there. Always to press rearward on the seatback be sure it is locked. 1-9